1. Field of the Invention
The present invention relates generally to an arrangement for noninvasively detecting biocurrents in an organism, and more particularly pertains to a method of noninvasively detecting both alternating and direct biocurrents in living organisms which is implemented in an extremely useful medical diagnostic instrument.
2. Discussion of the Prior Art
The flow of electric currents in a biological organism play a major role in its life processes. Small biocurrents range in magnitude from one microampere, associated with the firing of a small nerve, to almost one milliampere, occurring during a heart muscle contraction. Biocurrents are generally known to be associated with the heart, muscle and nervous systems. In addition, biocurrents are known to be generated during the growth process and also during the process of wound healing in tissue. Within the past several years it has also become generally recognized that injured, diseased, or cancerous tissues also generate bioelectric currents. These currents, unlike pulsing muscle and nerve currents, are steady in magnitude and appear immediately with the injury or tumor and disappear only if the problem disappears. It is known, for example, that the heart generates an "injury current" coincident with a heart attack which is apparently proportional in magnitude to the amount of tissue affected. It is also known that the degree of malignancy of a cancer tumor is related to the magnitude of its generated bioelectric current, and also that benign cysts, for example, generate no biocurrents.
The measurement of DC biocurrents has been extremely difficult in particular. Very low frequency and direct currents are difficult to impossible to measure noninvasively at present, yet are known to carry significant diagnostic and prognostic information relating to both heart disease and cancer. Skin electrodes do not work well at all as noise and artifacts generated by biopotential electrodes obscure any small potentials appearing on the skin from diseased internal organs. The study of DC currents has been conducted by researchers by surgically placing electrodes directly on the tissue of interest, which has not resulted in satisfactory measurements.